Siren for fire alarm



FIG. 1 is a front elevational view of a siren for a fire alarm showing my new design;

FIG. 2 is a bottom plan view thereof, with the top plan being a mirror image;

FIG. 3 is a right side elevational view thereof, with the left side being a mirror image;

FIG. 4 is a perspective view thereof. 

The ornamental design for a siren for a fire alarm as shown and described. 